The present invention relates to a cooling system for a fuel cell system, to an operating method and to a correspondingly equipped vehicle.
Research on motor vehicles with fuel cell drive systems (FCV: “Fuel Cell Vehicle”; FCHV: “Fuel Cell Hybrid Vehicle”) has been in progress for several years. DE 101 42 923 A1, for example, describes a drive assembly for a vehicle driven by a fuel cell and an internal combustion engine.
For use in motor vehicles with a fuel cell drive system, low-temperature polymer electrolyte fuel cells (NT-PEM fuel cells) are employed, in particular. Although the permissible maximum operating temperature of low-temperature polymer electrolyte fuel cells has risen significantly in the last few years and is currently around 90° C., cooling fuel cell vehicles at nominal load under extreme environmental conditions is still a challenge. Since low-temperature polymer electrolyte fuel cells customarily have only a comparatively low exhaust gas enthalpy flow, the thermodynamic conversion losses of the fuel cell are usually borne more or less completely by the cooling system. Usually, however, the flows of cooling air that can be achieved in a passenger vehicle are speed-dependent and are limited by the shape of the body, packaging etc.
DE 10142923 A1 describes a hybrid drive arrangement for vehicles driven by a fuel cell and an internal combustion engine, said arrangement having a common cooling device for the fuel cell and the internal combustion engine.